Apex Optic Mount for ACRO/MPS* - Sig P320 RX and RX Pro
Pros & cons
What works
- 28g weight adds minimal slide mass versus 35g aluminum competitors
- 3.2mm height maintains low bore axis while accommodating optic clearance
- Grade 8 screws withstand 45% higher torque than standard hardware
- Black oxide finish provides 500+ hour salt spray corrosion resistance
Trade-offs
- No included thread locker applicator - requires separate purchase
- Limited to RX/Pro cuts only - incompatible with common rev2 slides
- Adds 0.125" to optic height versus direct milling solutions
Video review
Expert review
Specs at a glance
About this product
The Apex Optic Mount for ACRO/MPS* - Sig P320 RX and RX Pro is a precision-machined steel mounting solution designed to securely interface Aimpoint ACRO P-1/P-2, Steiner MPS, and Lead & Steel Pandora PB-3 optics with Sig Sauer P320 slides featuring the factory RX Classic or RX Pro optic cuts. This mount addresses the specific dimensional requirements of the enclosed emitter optic category while maintaining compatibility with the P320's loaded chamber indicator system. Machined from billet steel and finished with black oxide, it represents a dedicated approach to mounting robustness in competitive and duty environments.
What is the Apex Optic Mount used for?
The Apex Optic Mount serves as a direct interface between enclosed emitter red dot sights and Sig P320 RX/Pro slides that lack native ACRO/MPS footprint compatibility. It transforms the slide's existing optic cut pattern to accept the specific mounting requirements of Aimpoint ACRO, Steiner MPS, and compatible optics while preserving zero under recoil. The included optic sub-plate ensures full locking bar engagement, preventing the optic from walking during sustained fire or impact.
How does the Apex Optic Mount compare to CHPWS plates?
The Apex mount offers superior material integrity compared to CHPWS's aluminum plates, with steel construction providing approximately 30% greater shear strength for the same cross-section. While CHPWS plates typically employ titanium fasteners, Apex utilizes grade 8 steel screws that withstand 45% higher torque values without thread deformation. The Apex system excels in hard-use scenarios where impact resistance outweighs weight savings, making it better suited for duty-grade applications.
What does it weigh and what are the dimensions?
The mount weighs 28 grams with a footprint measuring 34mm x 24mm and adds 3.2mm of height to the optic-slide interface. This specific geometry maintains a consistent 1.2mm wall thickness throughout the mounting platform, ensuring rigidity without excessive bulk. The total assembly increases overall slide weight by less than 5% compared to direct-mount solutions, minimizing impact on cycling dynamics.
Who is this NOT for?
This mount is unsuitable for P320 slides with the rev2 optic cut pattern (identified by "-R2" in the SKU), requiring part #112-009 instead. Operators seeking minimalist weight reduction should consider direct-mill solutions that eliminate the adapter plate entirely. The mount also provides no benefit for users whose optics already match the slide's native footprint, such as those using Romeo1Pro or Deltapoint Pro patterns.
What's in the box?
The package contains the main mounting plate, optic sub-plate, two grade 8 steel mounting screws, and thread locking compound sufficient for 3-4 applications. All components arrive sealed in anti-corrosion packaging with torque specifications printed directly on the insert. The kit accommodates exactly one optic installation with no spare hardware provided, consistent with our 4" Pillar File approach to component-specific packaging.
Is the Apex Optic Mount worth it at $75?
At $75, the mount delivers measurable value for operators requiring reliable ACRO/MPS mounting on RX-cut P320s, costing 40% less than slide remilling services. The steel construction ensures durability through approximately 10,000 rounds of testing without screw loosening or plate deformation. For competitive shooters transitioning between optic systems, this represents a cost-effective alternative to purchasing multiple dedicated slides, as detailed in our Action Enhancement Kit for CZ P-10 methodology.
Key attributes
| Material | Billet steel |
| Finish | Black oxide |
| Compatibility | Sig P320 RX/RX Pro slides |
| Optic Pattern | ACRO/MPS footprint |
| Weight | 28 grams |
| Height Added | 3.2mm |
| Included Hardware | 2 screws, sub-plate, thread locker |
Frequently asked questions
- Is it compatible with P320 X-Five Legion slides?
- Yes, provided the X-Five Legion slide has the RX Classic or RX Pro cut pattern. Verify your slide's SKU does not contain "-R2" designation, which indicates incompatible rev2 geometry. X-Five Legion models manufactured after Q3 2022 typically use the rev2 cut.
- Does it fit Holosun 509T optics?
- No, the 509T uses a distinct mounting pattern requiring separate adapter plates. This mount exclusively supports Aimpoint ACRO P-1/P-2, Steiner MPS, and Lead & Steel Pandora PB-3 footprints. Holosun compatibility requires their proprietary ACRO-to-509T adapter.
- How long does installation take?
- Proper installation requires 15-20 minutes including degreasing, thread locking application, and torque verification. Use a calibrated torque wrench set to 12-15 in/lbs for the mounting screws. Allow 24 hours for thread locker cure time before live fire.
- Can I return it if it doesn't fit my slide?
- Returns are accepted within 30 days if the mount shows no installation marks or thread damage. Customers must verify slide compatibility using Apex's online guide before purchase. Incorrect model purchases qualify for exchange toward part #112-009 for rev2 slides.